When we develop a system of font styles, we are essentially building the grammar of the map. The combination of labels and symbols helps our audience learn new features by comparing them to the structures used for familiar features.
The first piece of this is the map hierarchy. When we assign fonts by feature class, size, or importance, we are helping our map reader quickly determine which parts of the map should be viewed first. Large, bold fonts leap forward and demand attention, while smaller and lighter fonts recede, providing information when needed, but not assertively.
We can also use fonts as variables. The contrast between serif and sans-serif lends itself to qualitative distinctions. Any time we change fonts, even if they are both serif or sans-serif, we are clueing our reader into a change in information. Color, form, and width can also indicate...
